feat(db): migrate from MySQL to PostgreSQL

Replace MySQL driver with pgx/v5 and pgxpool:
- Update sqlc to use postgresql engine
- Convert query.sql to PostgreSQL syntax ($1 params, CASE WHEN,
  ANY() arrays)
- Replace sql.DB with pgxpool.Pool throughout
- Change nullable types from sql.Null* to pgtype.*
- Update ID types from uint32 to int64 for PostgreSQL compatibility
- Delete MySQL-specific dynamic_connect.go
- Add opentelemetry.gowrap template for tracing

chdb/logscores.go

@@ -220,7 +220,7 @@ func (d *ClickHouse) LogscoresTimeRange(ctx context.Context, serverID, monitorID
 				samples = append(samples, map[string]interface{}{
 					"id":           row.ID,
 					"monitor_id":   row.MonitorID,
-					"ts":           row.Ts.Format(time.RFC3339),
+					"ts":           row.Ts.Time.Format(time.RFC3339),
 					"score":        row.Score,
 					"rtt_valid":    row.Rtt.Valid,
 					"offset_valid": row.Offset.Valid,